化工循环水泵汽蚀原因分析与改进

Cause Analysis and Improvement of the Cavitations of Chemical Circulating Pump Cavitations

针对循环水系统循环水泵长期存在的现场泵体噪声高、振动偏大、效率偏低、叶轮磨损等问题,经过分析,设计缺陷导致的汽蚀是造成以上问题的主要原因。通过对叶轮进口冲角进行核算,采取增大叶轮入口直径、优化叶轮进口冲角等方式对叶轮进行改造,并结合改善叶轮流道光滑度的方法,提出了有效改进叶轮汽蚀的方案。改造后实际运行效果及拆检情况证明,泵抗汽蚀能力明显提高,泵体振动值最高下降1.5 mm/s,泵效率由72%提高至80%。在叶轮材质不变、流量不变、不增加有效汽蚀余量的基础上,通过对叶轮的改造,有效提升机泵抗汽蚀能力,同时达到减振和节能提效的目的。

Aiming at the problem of loud noise,high vibration,low working efficiency and impeller abrasion etc.of the circulating water pump in circulating water system,based on analysis,we found that design defect which leads to cavitations is the main cause of the problems above.By calculating impeller inlet attack angle,we adopted the strategies of increasing diameter of the impeller inlet,optimizing impeller inlet attack angle etc.to modify the impeller.Also,by improving impeller passage smoothness,effective strategy to improve impeller cavitations is proposed.After modification,the actual operation effect and the overhaul proved that the pump resisting cavitations capability was significantly improved,the pump body vibration value decreases maximum to 1.5mm/s,and the pump efficiency was increased from 72%to 80%.On the condition of not changing impeller material,not changing flow rate and not increasing NPSHA,the pump's capability of resisting cavitations can be improved effectively and achieve reducing vibration,energy saving and efficiency increasing by modifying the impeller.